The present invention is directed to a gas laser with at least one excitation tube wherethrough gas is axially flowing said laser comprising an electrode arrangement for electrical excitation of the gas within said tube and with at least one gas inlet and one outlet arrangement with respect to said excitation tube.
It is known that one serious problem of axial gas laser is the occurrence of wide-areal gas turbulances within the excitation tube which occurrence should be prevented. The above expression "wide-areal" which will be used further in this description shall be defined as follows:
Turbulances within a tube or a pipe are said "wide-areal" if the turbulance pattern seen in cross-sectional view has one turbulance center over the entire cross-sectional area of the tube. If turbulances occur with more than one center disposed within the tube's or pipe's cross-sectional areas they are said to be "small areal".
The characteristics of turbulance along the excitation tube are highly influenced by the characteristics of a gas inlet zone and/or of a gas outlet zone for the gas with respect to the excitation tube and are mostly severely disturbed by these latter zones because in these zones a radial incoming gas flow must be directed in more axial direction at the inlet zone and a gas stream from more axial direction must be directed in more radial direction at the outlet zone which features may directly or by reaction cause said unwanted wide-areal turbulances throughout the excitation tube.
It is an object of the present invention to prevent at a gas laser of the kind mentioned above occurrence of such wide areal turbulances and especially to prevent said inlet and outlet zones to generate such turbulances. To fulfill this target inlet and/or outlet arrangements of the gas laser comprise inlet and/or outlet means for said gas which are distributed around the circumference of the excitation stage tube said means steadily leading said gas from more radial into a more axial direction with respect to said tube for inlet and/or from a more axial direction into a more radial direction for outlet.
By these inventive features a uniform distribution of gas streaming into the tube or streaming out of the tube is reached and the steady changement of gas flow direction prevents occurrence of the harmful wide-areal turbulances within the excitation tube. These inventive features and others which may further improve will become obvious from the following figures and the accompanying description. Specific examples of the invention are thus described by way of the following Figures.